WAAS Space Segment

The Wide Area Augmentation System (WAAS) is the United States Satellite Based Augmentation System. The programme, started in 1992, is being carried out by the Federal Aviation Agency (FAA)[1] and is specially developed for the civil aviation community.[2] The system, which was declared operational in late 2003,[3] currently supports thousands of aircraft instrument approaches in more than one thousand airports in USA and Canada.[4] WAAS service area includes CONUS, Alaska, Canada and Mexico.[5] The WAAS programme is continuously in evolution; two development phases have been already covered, a third is in progress, and there are plans to improve the capability of the system in parallel with the evolution of the SBAS standards towards a dual-frequency augmentation service.[6]

WAAS Space Segment

The WAAS Space Segment is composed by several geosynchronous communication satellites (GEO) in charge of broadcasting, over the WAAS service area, the WAAS augmentation message.

Current WAAS GEO Coverage (June 2011)

As of June 2011, the Space segment consists of 3 commercial GEO satellites, Inmarsat-4 F3, Telesat's Anik F1R, and Intelsat's Galaxy 15, which has resumed service in March, 2011.[7]

The list of GEO satellites used in WAAS (also in the past) are in the following table:[8]

WAAS GEO Satellites (adapted from Wide Area Augmentation System article in Wikipedia)[8]